I have a complex pivot that produces annual ratios. I need to calculate the standard deviation of those ratios. Below is a sample of what the data looks like.
My pivot is like table 1, and uses as Sum(if(X,1,0)) construction for the numerator and a Sum(Total <A,B> if(X,1,0)) construction for the denominator. I can't share my actual data, so the below is sample ratios.
| Table 1 |
| Item | Year | Ratio 1 | Ratio 2 |
| A | 2012 | 0.25 | 0.81 |
| A | 2011 | 0.64 | 0.32 |
| A | 2010 | 0.25 | 0.36 |
| A | 2009 | 0.54 | 0.97 |
| A | 2008 | 0.01 | 0.63 |
| B | 2012 | 0.13 | 0.44 |
| B | 2011 | 0.54 | 0.04 |
| B | 2010 | 0.61 | 0.38 |
| B | 2009 | 0.69 | 0.69 |
| B | 2008 | 0.19 | 0.33 |
| C | 2012 | 0.23 | 0.94 |
| C | 2011 | 0.32 | 0.97 |
| C | 2010 | 0.45 | 0.50 |
| C | 2009 | 0.26 | 1.00 |
| C | 2008 | 0.57 | 0.75 |
| | | |
| Table 2 | |
| Item | StDev A | StDev B | |
| A | 0.25 | 0.28 | |
| B | 0.25 | 0.24 | |
| C | 0.14 | 0.21 | |
